A cellular communications network typically includes a variety of communication nodes coupled by wireless or wired connections and accessed through different types of communications channels. Each of the communication nodes includes respective protocol stacks that process the data respectively transmitted and received over the communications channels. Depending on the type of communications system, the operation and configuration of the various communication nodes can differ and are often referred to by different names. Such communications systems include, for example, a Code Division Multiple Access 2000 (CDMA2000) system and a Universal Mobile Telecommunications System (UMTS).
Third generation wireless communication protocol standards (e.g., 3GPP-UMTS, 3GPP2-CDMA2000, etc.) may employ a dedicated traffic channel in the uplink (UL) (e.g., a communication flow from a mobile station (MS) or User Equipment (UE) to a base station (BS) or NodeB). The dedicated channel may include a data part (e.g., a dedicated physical data channel (DPDCH) in accordance with UMTS Release 99/4/5/6 protocols, a fundamental channel or supplemental channel in accordance with CDMA2000 protocols, etc.) and a control part (e.g., a dedicated physical control channel (DPCCH) in accordance with UMTS Release 99/4/5/6 protocols, a pilot/power control sub-channel in accordance with CDMA2000 protocols, etc.).
A Radio Frequency (RF) carrier in a wireless communication system is a fixed span of wireless spectrum band in which wireless signals are transmitted and received accordingly. In current Third Generation (3G) wireless systems, for the sake of simplicity and fast-time-to-market requirements, each user is only required to support a single carrier (SC) at any given time. Currently both the Third Generation Partnership Project 2 (3GPP2) and the Third Generation Partnership Project (3GPP) consider SC systems and define 1.25 MHz and 5 MHz spectrum for Frequency Division Duplex (FDD) and high chip rate Time Division Duplex (TDD), and 1.5 MHz spectrum for low chip rate TDD, as a unit of one carrier bandwidth for wireless communications.
However, with increasing competition pressures from wideband technologies, such as Worldwide Interoperability for Microwave Access (WiMax, with spectrum of 20-135 MHz) and Ultra Wideband (UWB, with spectrum of 500 MHz), an effort is under way both in 3GPP and 3GPP2 to support multi carrier (MC) systems. MC systems are different from SC systems, in that MC systems may distribute each user's traffic flow among multiple carriers rather than a single carrier. Distributing data to a user using multiple carriers and having each user support more than one carrier would provide data throughput 10 to 20 times higher than the data throughput of today's 3G systems.
Since most QoS control mechanisms are closely related with packet switched domain, FIG. 1 illustrates a conventional wireless communication system 100 operating in accordance with UMTS packet data protocols. Referring to FIG. 1, the wireless communication system 100 may include a number of NodeBs 110, each serving the communication needs of a user equipment UE 105 in a respective coverage area. The NodeBs 110 are connected to a radio network controller (RNC) 120. RNCs are connected to a Serving GPRS Support Node (SGSN) 130. The RNC 120 handles certain call and data handling functions, such as, autonomously managing handovers without involving a SGSN 130. The SGSN 130 handles routing calls and/or data to other elements (e.g., RNCs 120) in the Radio Access Network (RAN) 170 or to a core network including for example, a Gateway GPRS Support Node (GGSN) 140, a Policy Decision Function (PDF) 150 and an Application Function (AF) 160.
FIG. 2 illustrates a convention wireless communication system operating in accordance with CDMA2000 1xEV-DO protocols. Referring to FIG. 2, the wireless communication system 200 may include a number of base transceiver stations (BTS) 220, each serving the communication needs of user equipment or mobile stations (MS) 205 in a respective coverage area. The BTSs 220 are connected to a BSC 215. The BSC 215 is connected to a Packet Control Function (PCF) 225. The PCF 225 is connected to a Packet Data Serving Node (PDSN) 210, which is connected to a home Authentication, Authorization and Accounting Server (AAA) 230. BTSs 220 and BSC 215 of the conventional wireless communication system 200 function similar to their counter parts, NodeBs 110 and RNCs 120, respectively, in the conventional wireless communication system 100. Likewise, PCF 225 of wireless communication system 200 functions similar to SGSN 130 of wireless communication system 100; PDSN 210 of wireless communication system 200 functions similar to GGSN 140 of wireless communication system 100.
NodeBs 110 and BSC 215 typically include a scheduler implementing a scheduling algorithm that schedules (e.g., establishes transmission rates, etc.) for the UEs 105 and MSs 205. Various RF carrier scheduling algorithms such as Round Robin (RR), Highest Rate User First (HRUF), Shortest Remaining Processing Time fast (SRPT), Proportional Fairness (PF) etc. are well-known in the art and used to schedule UEs 105 and MSs 205 for transmission. However, none of the conventional scheduling methods can be implemented effectively in a MC system.